Recrystallization of amylopectin in concentrated starch gels

The relation between the recrystallization of amylopectin and the increase in stiffness of starch gels during storage was studied by various techniques. From transmission electron microscopy it was concluded that the size of the crystalline domains in retrograded 30% w/w potato starch gels was about 5 nm, much smaller than those present in native starch. The super-helical structure formed by the crystalline domains in native starch granules was not seen. It may thus be concluded that in retrograded starch gels the long range ordering is not regained during retrogradation. The relation between the degree of recrystallization, as determined with differential scanning calorimetry (DSC), and the increase in stiffness, as measured in compression, was found to be closely related. Two mechanisms will be discussed which may explain these observations. Copyright (C) 1996 Elsevier Science Ltd